Merge branch 'mv/merge-recursive'

* mv/merge-recursive: builtin-merge: release the lockfile in try_merge_strategy() merge-recursive: get rid of virtual_id merge-recursive: move current_{file,directory}_set to struct merge_options merge-recursive: move the global obuf to struct merge_options merge-recursive: get rid of the index_only global variable merge-recursive: move call_depth to struct merge_options cherry-pick/revert: make direct internal call to merge_tree() builtin-merge: avoid run_command_v_opt() for recursive and subtree merge-recursive: introduce merge_options merge-recursive.c: Add more generic merge_recursive_generic() Split out merge_recursive() to merge-recursive.c